1. The Field of the Invention
The present invention relates to a method and apparatus for processing sausage. The invention may be used for linking stuffed casing to form individual sausages of uniform length and separating the individual sausage links and may also be used to separate sausage links which have been formed by other apparatus.
2. Prior Art
Machines for automatically linking a filled sausage casing have been in use for some time. These machines normally function by a twisting process in which a portion of the filled casing is pinched at intervals along its length, and the casing is twisted to form an individual link. As the casing is twisted, the meat emulsion or other filling material in the casing is forced away from the twisted portion of the casing, thereby forming individual links. Machines of this type are described in U.S. Pat. Nos. 1,886,497; 3,435,482; 2,663,982; 3,191,222; 3,264,679; 3,971,101 and 4,073,039. There are also numerous other patents which disclose specific mechanisms for accomplishing the same result. In these twisting processes, the meat emulsion or other filling material within the casing is forced from the end of the link because of the reduction in the size of the casing as it is twisted. This twisting process puts significant amounts of stress on the casing material, and there is a tendency for the casing material to break as it is twisted. Although these twisting processes have been found to be commercially acceptable when using casings made from materials having high tensile strength, such as cellulose, the twisting process causes some problems with natural casings, such as animal intestines, and with collagen casing materials. These materials do not have the tensile strength of the cellulose casing material, and there is a greater tendency for the casing to tear or break, thus, causing unacceptable products and waste.
In addition, the twisting mechanisms used to form the links are quite complicated and expensive. Because of the complexity of these machines, the machines are difficult to clean and maintain in a sanitary condition. The complexity also results in excessive maintenance and repair costs. In order to form sausage links of a different length, it is necessary to replace a significant portion of the machine, which leads to a high cost for parts. The machines also require extensive down time to convert the machines in the event the sausage producer desires to produce sausage links of a different length. The twisting machines also cannot form links from small diameter, i.e., less than 16 mm., stuffed casing.
Commercially available linking machines using a twisting mechanism occupy a large amount of floor space in refrigerated processing areas. As refrigerated space in commercial sausage operations is expensive, linking machines of a smaller size are desirable.
Production of links of uniform length by a twisting mechanism requires that a standard amount of twist be imparted to each sausage and that the filling of the sausage casing be uniform. Prior art twisting mechanisms have a tendency to produce links of various lengths. This occurs because of variations in the stuffing of the sausage casings and the variations in twisting imparted by the machine. If the casing is underfilled, then more casing is gathered in the twist, and a shorter link results. If overfilled, a longer link results. Sausage emulsion characteristics also have an effect on length. As an example, high viscosity filling reduces the twisting efficiency of the machine resulting in longer links.
The forming of sausage links without twisting has been disclosed in U.S. Pat. Nos. 3,059,272; 3,208,099; 3,209,396; 3,220,053 and 3,228,060. In the process disclosed in these patents, a plurality of stuffed casings are contacted with a series of slotted bars mounted on a conveyor. The casing is forced into the slots and constricted to form individual links. The formed links are carried by the conveyor through various processing steps to cook or cure the sausage. The attached links are removed from the conveyor, and the casing is removed from the links, thereby freeing individual sausages. This process is intended to be used with high tensile strength casings of the cellulose type.
In some sausage processes, the links are cooked and further processed in a continuous chain of links. The chain must be cut into individual links in a separate step. Existing apparatus employed to cut the preformed links into separate links are quite complicated considering the operation that they perform. These machines often do not properly register their cutting mechanism with the length of the link and, therefore, cut the sausage link itself rather than cutting the twisted casing between adjacent links. These machines often employ complicated and expensive electric-eye sensors and other technically sophisticated mechanisms. Even when the indexing is proper, cutting occurs indiscriminately at any point between adjacent links. Aesthetically it is better to center the cut between links so that equal amounts of the twist are left on either end.